1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a flash memory cell by using a trench method which can acquire a margin of subsequent processes as well as making a logic and a flash memory into one chip by forming a floating gate of the flash memory within a shallow trench isolation (STI).
2. Description of the Related Art
In the prior art, the floating gate of a flash memory is formed on a Si wafer, thus a height generated upon forming the floating gate imposes a burden on a contact process and becomes more serious as the process technique becomes finer. Further, from the viewpoint of making one chip with logic, an increase in the stepped portion during a logic process and a flash memory process causes a reduction in the margin of a contact process and the subsequent processes.